The invention relates to dispensing devices e.g. intended for the distribution of medicaments used in very small doses or to the distribution of perfume samples. Such devices are designed around known miniature dosing pumps with a piston carrying an axial movable nozzle and whose body substantially has a diameter of approximately 7 mm for a length of approximately 3 cm, under an assembly collar projecting by approximately 1 mm, but which is not necessarily circular, whereby their outer volume may not exceed 4 or 5 cm.sup.3, with a diameter of approximately 10 to 12 mm, while their capacity varies between about 50 and 10 doses, i.e. drops to 1 ml.
The above type structure makes it possible to construct such devices in very large numbers at very low cost. It can also apply to slightly larger models, but its characteristics would then generally lose part of their interest.
Known dispensing devices include a pump carrying the internal mechanism disposed in a container part of the device. The pump has a flange which rests on the upper edge of the container and which is connected to an outer bush member. The bush member is fitted on an outer bearing surface of the wall of the container. A construction of the surface of the wall of the container. A construction of the type just described is the subject of U.S. Pat. No. 4,311,255. There, the bush member forms a can covering the entire length of the container.
The adoption of a generally cylindrical shape for the container and for the bush member makes it possible to make them from synthetic materials and more generally thermoplastic materials, which are injection molded in the same way as most of the pump components. If the container fits along the pump in glove finger-like manner, it leads to minimum transverse dimensions. Unlike other assembly methods, this method enables the cross-section of the device to slightly vary from a circular contour, while retaining a substantially uniform thickness of the wall.
The assembly only exerts easily withstood compressive stresses on the components, and with regard to such small components, the precision inherent in injection molding makes it possible to bring about a substantially non-dismantlable, tight assembly.
The assembly of the device can take place on an already filled container using existing machines, after a small number of modifications have been made, by engaging the bush member to which the pump has already been attached to form a sub-unit. In order to facilitate the assembly operation, the bush member can carry a ring locking the collar of the pump to the bush member.
Numerous materials are available and they will be chosen as a function of the product to be stored and will preferably be relatively rigid in order to avoid deformations, but without creating excessive local stresses.
One obstacle to be overcome in the assembly of the parts of the dispensing device is the obvious need of evacuating the occluded air from the container as the bush member and pump are assembled into the container. For this purpose, the prior art device, such as show in U.S. Pat. No. 4,311,255, have constructed the container part or bush member with interfacing longitudinal grooves through which the air can escape from the container during assembly of the device. With such constructions, the container and bush member are sealed at the end of the assembly operation by axial abutment of the upper end of the container against an upper cover wall of the bush member.
This solution has apparently not been industrially realized. The reason for this may be that the inversion of the curvature created on the wall of the container to form the grooves makes it necessary to reinforce the latter, which is not very acceptable in the case of miniature devices. Also, it would be difficult to obtain the precision necessary for the final sealing on the abutting end of the grooves.